In my prior U.S. Pat. No. 3,887,953, a raft is disclosed which is adapted for use as a water rescue or recovery litter. The raft is intended for use primarily by stand-by units on duty at power boat races to facilitate the safe and speedy rescue of injured drivers. When used for this purpose, the raft may be dropped from a helicopter at the site of the emergency. After the injured driver is placed aboard the raft, the raft may be picked up by the helicopter and transferred to an ambulance or to a hospital.
One of the dangers in picking a raft up out of the water by a helicopter is the possible transmission of a static charge of electricity from the helicopter to the raft. The helicopter will normally generate a substantial charge which if not grounded can do serious harm to persons in contact with the raft.
Accordingly, one of the objects of the invention is to provide a device by means of which a raft may be picked up out of the water which will ground the electricity and dissipate any static charge without subjecting the raft or its occupants or its attendants to an electric shock.
Another object of the invention is to provide a device for suspending a raft from a helicopter having straps for picking up the raft and a ground wire which is sufficiently longer than the straps so as to contact the water and ground the helicopter before the straps contact the raft.